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If you would have read, and followed the FSM, you would be done already (with time to get, and prep parts). If the aftermarket bearings are designed to be used with the unit, and the design was done by a reputable company, they will work equally well as OEM parts. The FSM says to use 0.006 on each side for preload (that is from GM, and they may know what they are doing). You may find that the preload can move the mesh/lash 0.001 or so (mine went from 0.009 to 0.010), The lash allows for expansion of the parts from heat. Tolerances are there to allow for small variables in assembly. As long as you are within tolerance, you will be safe. The shop that builds rears, uses the same parts that you have access to, and if they are good enough for them, they will work for you. The only thing you need to concern yourself with, are the correct assembly, tolerances, and mesh pattern. The GM setup in my 91 OCC has 281K miles on it, and it still works fine. It even handles my 454 (461) without complaining. You can use redesigned parts, and spend a lot more money if you want to, but it will have virtually the same result.

The preload of a bearing will determine the life of the bearing. The range from just tight to a range of preload will at one point have the longest bearing life, then it will deteriorate past that point. If GM says that the best preload is a certain value, you can pretty much put your money on that number being the peak wear preload. If you mess with the number either way, it will decrease the life of the bearing.

Just a thought on pinion shims, since you are concerned with the fit around the pinion shaft: If the 7.5 inch rear has a smaller diameter pinion shaft, the shims for it may have a smaller inside diameter, and fit the 8.5 inch shaft much tighter. Just use the same thickness. If they are too small, you can always hone, or grind them to fit over the shaft. You still need some gap between them for expansion from heat, so they do not bind.
 
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'The factory ( double check this ) side bearing preload spec is basically .008 to .010 more"
Is why I said to check, as that was coming off the top of my head.
Thanks Fred for clarifing the number.
OP, Fred's your guy he can walk you through the rest.
 

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Discussion Starter #64
For what it’s worth, the carrier bearings measure .775 and the ear arbor for that same inner ring measures .808. My numbers are ballpark in the sense they may vary a couple thousandths but just saying some of the ear on the differential will be proud through the bearing inner diameter. I’ve checked that the shims slip over the proud Area. Just tossing this out there in case there’s a red flag. Again, I’d hate to be stuck with these parts. I don’t don’t have cash to use as door stops. Also, I’m reading all your posts and keeping the information ready.
 

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Discussion Starter #65
I need to get some brake kleen to knock some of this rust preventative oil off the gear and to clean the ring gear thread holes and bolts. I’m probably going to mount the ring to the diff and then the press on the side bearings. Clean, file burs off, pre tight a surrounding few, lock tight, torque the others. Then press carrier bearings on. All this while thinking and ordering the pinion kit
 

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But the bearing and outer race , together, are wider than the stub.
About .
20200103_130439.jpg
20200103_130319.jpg
846 rough quick measurement here

Also snapped you a picture of

8.5 oe size
The special bearing to use the thick stub in 8.5

And the 8.6 also 12 bolt
 

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Discussion Starter #68
But the bearing and outer race , together, are wider than the stub.
About . View attachment 192207 View attachment 192208 846 rough quick measurement here

Also snapped you a picture of

8.5 oe size
The special bearing to use the thick stub in 8.5

And the 8.6 also 12 bolt
Thanks for shining some light in that. I put both inner and outer together here on my end and come up with the same .852 as you are showing.
 

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Discussion Starter #69 (Edited)
Well, I’m confident I’m seated flat and clean. Not torqued yet, just snug. I’m going to torque a percentage (like wagon 95 said earlier in the thread) on all bolts, then re torque with red loctite individually. Can I get a torque spec? The Trutrac booklet says go by the FSM or the ring and pinion manufacture which in my case is Motive Gear. I’m going to have to stop until I see what Motive says as I’m dealing with their bolt threads. Opinions, numbers and reminders on this is welcome.my vise is too small to hold the thing too so just taking it as I see it. I pretty much cleaned it, debarred it, ran the bolts in the threads and out by hand, sprayed and blowed them. Pulled the ring to the flange parallel while aligning the bolt holes. Put the bolts in and snugged them to the press diameter section of the diff. Hand snugged. Turned the diff over and tapped the ring to seat. The thing was pretty cold from the brake cleaner spray. It didn’t take much force tapping. It went on pretty nice. Oh and a film of clean motor oil to start. I then re snugged only to the point it won’t let a gap reappear. Waiting on final torquing. Thanks.
 

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Discussion Starter #70
For what it’s worth, no pamphlet with the Gear Set. Just ring and pinion in a foam boxing, in another box. So, I’m calling them.
 

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Discussion Starter #71
For what it’s worth, I just got off the phone with Motive Gear and they say 60 to 65 ft lbs torque for the ring gear. The Impala SS FSM says 89ft lbs. I’m going with the 60 to 65 ft lbs. The man told me thread locker is more important than the torque. I’m just sending the message. My only guess is the gears are softer.
 

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Discussion Starter #72
First chalk mark 30 ft lbs. second chalk mark 60-65 with beam needle style torque wrench and red loctite. My torque wrenches don’t torque backwards. Let me know if I’m not knowing how to use them but this is the first application where I’ve needed to torque backwards. Also blowing out hole and wiping threads of bolts. They have already been brake cleaned.
 

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Discussion Starter #73
Is there any tricks to pounding these upper control arm bushings off? Am I even supposed to be pounding on cast like that? The rubber seems to be sticking out more than the metal part. Do I have to cut the rubber back and put a socket over and pound that? Because I don’t see any easier way as my hammer is going to bounce back at me.
 

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Help, Here's what I did.

Mark: Snowman-33
 

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Discussion Starter #75 (Edited)
Help, Here's what I did.

Mark: Snowman-33
Thanks much. I couldn’t get the drill bit to walk around the rubber like he did in the video but I did use a large semi pointed punch and heavy sledge hammer with a short handle to poke/push a bend in the bushing outer metal casing, caving it in and while tapping it through and out. I just made sure I didn’t deform the thing to the opposite form of smaller vs larger than the diff case bushing hole which may prevent it from sliding out. If that made sense. If anyone looks how my old parts have that dent fold there. That’s what I did, all that, after drilling the rubber out by rocking the drill back and forth chewing up as much of the rubber as I could and pounding the metal tubes out first. Thanks again.?
 

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Discussion Starter #76
Is there any Brand upper control arm bushings I should stay away from? I’m planning Rockauto. Are they all pretty much across the board? For kicks I’m wondering if mine are the stock? They are pink and an off white.
 

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Discussion Starter #78 (Edited)
Ive purchased the Ratech 1134 kit directly from Ratech. Ive also purchased a dial meter torque wrench ( a decent one). Better to get the torque preload accurate and correct. I guess I'll be working on making a yoke holder wrench and working on my set up bearing. I can do all this while im waiting for my torque wrench and Ratech kit.
 

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Discussion Starter #79
Just to shine some light for the curious out there, here is a picture of how the plug weld looks from the inside of the diff axle housing tube. There is some stamp which looks like “WTC”. I have no idea what that stands for. If anyone knows what that means, please share. I’ve done a search and can’t find any company names. Maybe it’s a steel company that makes the tubes? Also, I’m pointing out how the plug welds on my rear end look nice from the inside. The video where the mechanic says the plug welds leak. Mine won’t because they only show a burn mark, no cracks. The only way the plug welds could leak in my situation is for the press fit to become loose and seepage from the plug weld between the fittment if there’s a defect there. Hope this sheds some light for the wondering minds out there. Thanks
 

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Discussion Starter #80
Do you guys think this is going to be strong enough for a crush sleeve collapsing? It’s 1/4 inch thick. The reason I ask is because after I made this, I’m seeing people saying they are breaking these yoke wrenches. I know they strip the box hole out but I’m not going to use it that way. I plan on bolting a bar to it somehow. Maybe trim the sides a bit if I plan on keeping it.
 

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